Fig. 1. Simulated phase distribution of interference field^[26]

Fig. 2. Experimental diagram and interference fringe pattern of Michelson interferometer^[26]. (a) Diagram of Michelson interferometer; (b) fork fringe pattern

Fig. 3. Experimental diagram and interference fringe pattern of Mach-Zehnder interferometer^[26]. (a) Diagram of Mach-Zehnder interferometer; (b) fork fringe pattern

Fig. 4. Fork fringe pattern^[27]

Fig. 5. Schematic of experimental setup using TN-LCSLM^[34]

Fig. 6. Optical vortex array illuminator, vortex beam array intensity, and interference fringe diagram^[34]. (a) Hexagonal optical vortex array illuminator; (b) light intensity of vortex beam array; (c) fork fringe pattern

Fig. 7. Diffraction grating^[35]. (a) Grating A; (b) grating B

Fig. 8. Intensity, phase, and interference fringe diagrams of vortex beam array^[35]. (a) Point array of beam intensity; (b) phase distribution; (c) fork fringe pattern

Fig. 9. Schematic diagram of optical wedge diffraction method^[36]

Fig. 10. Simulation results of two columns of optical vortexes with opposite topological charge generated by single wedge^[36]

Fig. 11. Transformation relation diagram and transformation scheme diagram of mode converter^[37]. (a) Transformation relation between flower-like LG mode and crisscrossed HG mode; (b) transformation scheme between flower-like LG mode and crisscrossed HG mode

Fig. 12. Intensity and phase diagrams of vortex beam array^[37]. (a) Vortex beam array intensity distribution; (b) vortex beam array phase distribution

Fig. 13. Experimental result^[38]

Fig. 14. Schematic of experimental optical path^[38]

Fig. 15. Experimental diagram for OAM array encoding/decoding and distribution of beam arrays^[39]. (a) Schematic of experimental optical path; (b) Gaussian beam arrays; (c) vortex beam arrays; (d) topological charge of vortex beam arrays

Fig. 16. Rectangular vortex beam array with M rows and N columns^[40]

Fig. 17. Hologram and experimental interference fringes of vortex beam array^[40]. (a) Hologram of vortex beam array; (b) interference fringes of vortex beam array

Fig. 18. Schematic of experimental system^[42]

Fig. 19. Schematic of multi-channel vortex beam generator using metasurface^[51]

Fig. 20. Vortex beam arrays obtained by experiment and simulation^[51]